WestHam with 10-man players defeated Chelsea 11-man player to secure their first win of the season.
Nayef Aguerd got the first goal of the game for WestHam but Carney Chukwuemeka got the equalizing goal for Chelsea.
Michail Antonio strike gave WestHam the lead in the early minute of the second half, while Lucas Paqueta crowned the win with a penalty for WestHam in injury time.
Chelsea had the chance to take the lead in the 43rd minute when the referee points to the spot because Raheem Sterling was fouled towards the box by Tomas Soucek.
Argentine midfielder, Enzo Fernandez steps up to try to score his first Premier League goal with the penalty but Alphonse Areola guessed right pushed the shoot-out away.
Chelsea new signing, Moises Caicedo had a very shaky debut for Chelsea as he brought down Emerson in the box and the referee pointed to the spot.
WestHam midfielder, Lucas Paqueta stepped up to take the penalty and sent Robert Sanchez the wrong way to score the die-minute goal.
The referee blew the final whistle of the game leaving Chelsea with no win in their first two games and their first loss in the new season.
